Studies indicate that lowering the body temperature at an injured site can reduce swelling and pain while promoting healing. In many injuries, it is beneficial to the injured site to first lower the temperature for a short period of time, and then to apply heat to the same injured site.
There are various devices that individually provide a means to cool or to heat the injured site. A common technique to cool the affected area is to apply ice, usually in an ice pack. Although ice has the advantage of being inexpensive and readily available, it is not healthy to apply ice to the skin for prolonged periods of time. The temperature of the ice can damage skin if left for more than a few minutes in one area. As a result, ice only cools the upper surface of the skin and deep penetration of the cooling process does not take place.
Another means for localized cooling are cold packs made of two chemicals located in individual membranes. When the membranes rupture and the chemicals are allowed to mix, the mixing process causes an endothermic reaction that provides localized short term cooling. One disadvantage of the chemical cooling pack is that the packs are not reusable.
A more sophisticated means for cooling a body part is disclosed in U.S. Pat. No. 5,097,829 issued to Quisenberry. This device provides a temperature controlled fluid circulating system that controls fluid in a thermal blanket having a thermal electric cooling device wherein the temperature control fluid is cooled by the cold set of the cooling device and pumped through and from the blanket through first and second conduits. The conduits are connected to a sealed blanket formed of opposed sheets of vinyl material which are sealed together and define a plurality of passage ways between the sheets for the circulation of the cooling fluid.
Various heating devices are also available ranging from a heat lamp, a hot pack that is similar to the chemical cold pack discussed supra and a heating pad. The heat lamp has a disadvantage in that it is difficult to focus the heat to only the injured area without affecting surrounding tissue. The hot pack has the disadvantage that it can only be used one time when the membranes rupture and thereby mix the chemicals. A heating pad is disclosed in U.S. Pat. No. 4,042,803 issued to Bickford. The heating pad has flexible material that is adapted to be supported on a human body part, wherein an electrical heating elements are embedded inside the support material. The heating elements are connected to an electrical energy source for selectively heating the part of the body in contact with the sheet of material.
As with all of the aforementioned devices for heating and cooling, each device can only accomplish one activity. As a result, if trauma occurs to a body part that requires both the application of cold and heat to the affected body part, two separate devices are required. Therefore, it is advantageous to provide a device that can selectably provide both cold and heat to a body part. It is also advantageous to provide a device that can be used repeatedly. It is further an object of this invention that the device provides a flexible pad that can be wrapped about an injured portion of the body while providing heat or cold to the affected area. It is further an object of the invention to provide a device that is thermoelectrically controlled. Finally, it is an object of this invention to provide a device that controls and limits the temperature range so that the pad does not get too hot or too cold.